Technologies

Researchers at UC San Diego have successfully designed and synthesized a new class of inhibitors for New Delhi Metallo-betalactamase-1 (NDM-1) and two related beta-lactamases. They exhibit remarkable selectivity as they don’t hit other Zn(II) metalloenzymes. The inhibitors restored susceptibility to imipenem in three differentE.colistrains, including a clinical isolate expressing blaNDM-1.

Antibiotic-resistance in pathogenic bacteria has become a critical public health threat. A major mechanism of antibiotic resistance is microbial degradation of drugs by enzymes such as β-lactamases which degrade the β-lactam ring of β-lactam antibiotics, namely penicillins, cephalosporins, carbapenems and monobactams, inactivating them. There are four different molecular classes of β-lactamases (A-D). Three classes of β-lactamases (A, C, and D) utilize an active-site serine in covalent mechanisms that can be targeted by β-lactamase inhibitors coformulated with β-lactam drugs. In contrast, class B consists of metallo-β- lactamases (MBLs) that utilize one or two active site Zn(II) ion(s) to catalyze the hydrolysis of the β-lactam ring.The emergence of carbapenemase producing bacteria, especially New Delhi metallo-β-lactamase (NDM-1) and its variants, worldwide, has raised a major public health concern. NDM-1 hydrolyzes a wide range of β-lactam antibiotics, imipenem, meropenem, ertapenem, gentamicin, amikacin, tobramycin, and ciprofloxacin including carbapenems, which are the last resort of antibiotics for the treatment of infections caused by multidrug-resistant bacteria such as carbanenem-resistant Enterobacteriacae and Klebsiella pneumoniae. Currently, there are Inhibitors of NDM-1, both of which have liabilities, either due to adverse effects in mammals or off-target inhibitory activity. Therefore, a new type of NDM-1 inhibitor is needed.